© 1987 Heron Publishing—Victoria, Canada
Short-term canopy interactions of beech trees: mineral ion leaching and absorption during rainfall
S. Leonardi and W. Flückiger
Institute for Applied Plant Biology, Sandgrubenstraße 25, CH-4124 Schönenbuch, Switzerland / Received October 2, 1986
Summary
Mineral nutrient composition of the stemflow of 70–120-year-old beech trees Fagus sylvatica L. in 26 stands in northwestern Switzerland was compared with that of incident precipitation. Four mm of precipitation was
sufficient to wash-off the bulk of the dry deposition intercepted by the canopy. Thereafter, differences in composition between
precipitation and stemflow provided a measure of net ion absorption by or leaching from the canopy. Depending on the acidity
of the rain and on the buffering of protons by the canopy, different interactions were observed. Highest rates of leaching
were detected for potassium whereas ammonium was absorbed in some stands and leached in others. Absorption of chloride was
associated with the occurrence of H+ buffering. The latter took place to a greater extent in more acidic precipitations. Interrelations of short-term canopy ion
interactions are discussed and some implications examined.
